I don't know about the "new" EU members,... but between the "old" countrys, like France, Germany, Italy etc. there aren't checkpoints anymore, just signs
Recency of EU membership isn't always the determining factor. Not too many years ago there was still a traditional checkpoint between Germany and Denmark. When I went through all cars entering Denmark were being stopped.
Both countries are old members. I assume the control is because Germany is Schengen while Denmark is Scandanavian. The Scandanavian rules on importation of alcoholic beverages might have something to do with it also.